U.S. patent number 8,960,528 [Application Number 11/182,330] was granted by the patent office on 2015-02-24 for insulating cup wrapper and insulated container formed with wrapper.
This patent grant is currently assigned to Dixie Consumer Products LLC. The grantee listed for this patent is Claus E. Sadlier. Invention is credited to Claus E. Sadlier.
United States Patent |
8,960,528 |
Sadlier |
February 24, 2015 |
Insulating cup wrapper and insulated container formed with
wrapper
Abstract
A thermally insulated cup is formed from a single-walled paper
or plastic inner cup and an insulating outer wrapper. The
insulating outer wrapper comprises a paper base sheet or outer
sidewall blank, optionally printed on one side, and a corrugated
paper or foamed plastic insulating insert. The insulating insert is
similar in shape to the outer sidewall blank but smaller in size.
The insert is glued in a centered position to the non-printed side
of the sidewall blank to form a two-layered insulating wrapper.
Less than 20% of the area of the insert is glued to the base sheet.
Specifically, no glue is applied to the area adjacent to the cut
side edges of the insert, and as such these edges are not attached
to the base sheet. The wrapper is then wrapped around the single
walled inner cup. The side edges of the base sheet of the wrapper
overlap and are sealed directly together to form a side seam. The
side seam is itself adhesively secured to the side wall of the
inner cup. The side edges of the insert do not come between the
seal between the side seam of the base sheet and the inner cup. The
wrapper can also be adhered to the inner cup by one or more beads
of cold glue (paste adhesive) or a thin layer of polyethylene (or
similar heat sealing material) can be pre-applied to the inside cut
edges of the base sheet. This is then heat-activated immediately
prior to wrapping the wrapper around the inner cup, and pressing
the overlapping side seam to the sidewall of the inner cup to
simultaneously glue the side seam together, and to glue the
insulating wrapper to the side wall of the cup.
Inventors: |
Sadlier; Claus E. (Pleasanton,
CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Sadlier; Claus E. |
Pleasanton |
CA |
US |
|
|
Assignee: |
Dixie Consumer Products LLC
(Atlanta, GA)
|
Family
ID: |
35196861 |
Appl.
No.: |
11/182,330 |
Filed: |
July 14, 2005 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20060144915 A1 |
Jul 6, 2006 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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11098853 |
Apr 4, 2005 |
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10831411 |
Apr 22, 2004 |
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Current U.S.
Class: |
229/403;
229/939 |
Current CPC
Class: |
B65D
3/22 (20130101); B65D 81/3874 (20130101); Y10S
229/939 (20130101) |
Current International
Class: |
B65D
3/22 (20060101) |
Field of
Search: |
;229/403,939
;220/737,738,739 |
References Cited
[Referenced By]
U.S. Patent Documents
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IT |
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52076765 |
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Jun 1977 |
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52-14830 |
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52-148380 |
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57-6333 |
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61-142419 |
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291640 |
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2142878 |
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RU |
|
2010/109000 |
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Sep 2010 |
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WO |
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Other References
Walter Soroka, Fundamentals of Packaging, 1995, pp. 296-301:
Publisher: Richard Warrington, USA. cited by applicant .
Marilyn Bakker, The Wiley Encyclopedia of Packaging Technology,
1986, 66-69; USA. cited by applicant .
Office Action for U.S. Appl. No. 12/829,587 mailed Mar. 30, 2011.
cited by applicant.
|
Primary Examiner: Elkins; Gary
Attorney, Agent or Firm: Letson; William W.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This patent issued from an application that is a
continuation-in-part (CIP) of my application Ser. No. 11/098,853,
filed 4 Apr. 2005, now abandoned, which is in turn a CIP of my
application Ser. No. 10/831,411, filed 22 Apr. 2004, now abandoned.
Claims
The invention claimed is:
1. A thermally insulated cup wrapper, comprising: an outer base
sheet having a plurality of boundary edges and a corresponding
plurality of edge portions adjacent said boundary edges,
respectively; an insert sheet having a plurality of edges; at least
one of said outer base sheet and said insert sheet being made of
insulating material to provide an insulating layer; said insert
sheet being adhered to one side of said outer base sheet to form a
thermally insulated cup wrapper; said insert sheet being smaller in
size than said outer base sheet and being positioned on said outer
base sheet so that said plurality of edge portions of said outer
base sheet extend beyond said edges of said insert sheet wherein
said insert sheet is not attached to said outer base sheet along
the plurality of edges and said edges can migrate freely; whereby
said thermally insulated cup wrapper can be wrapped around and
adhered to a single wall cup to form a thermally insulated cup.
2. The thermally insulated cup wrapper of claim 1 wherein said
insert sheet is made of insulating material.
3. The thermally insulated cup wrapper of claim 2 wherein said
insert sheet is made of a material selected from the class
consisting of corrugated material and foamed plastic.
4. The thermally insulated cup wrapper of claim 1 wherein said base
sheet and said insert sheet each have a generally rectangular shape
with four bounding cut edges, two of said edges being opposite side
edges that are oriented at an acute angle to each other, the other
two of said edges being opposite top and bottom edges that are
curved and are oriented concentrically to each other.
5. The thermally insulated cup wrapper of claim 1 wherein said base
sheet and said insert sheet are made of paper.
6. The thermally insulated cup wrapper of claim 1 wherein said
insert sheet is coated with reflective material on at least one
side of thereof.
7. The thermally insulated cup wrapper of claim 1 wherein said
insert sheet is made of insulating material selected from the class
consisting of corrugated material and foamed plastic, said base
sheet and said insert sheet each have four bounding cut edges, two
of said edges being opposite side edges that are oriented at an
acute angle to each other, the other two of said edges being
opposite top and bottom edges that are curved and are oriented
concentrically to each other and said base sheet and said insert
sheet are made of paper.
8. The thermally insulated cup wrapper of claim 1 wherein less than
20% of said insert sheet is adhered to said base sheet.
9. A thermally insulated container, comprising: a cup having a side
wall, said side wall having an inside and an outside surface; a
thermally insulated cup wrapper being wrapped around and adhered to
said outside surface of said side wall of said cup; said cup
wrapper comprising a plurality of layers comprising an outer base
sheet and an insert sheet; said outer base sheet having a plurality
of boundary edges and a corresponding plurality of edge portions
adjacent said boundary edges, respectively; said insert sheet
having a plurality of edges; at least one of said base sheet and
said insert sheet being an insulating layer; said insert sheet
being adhered to one side of said outer base sheet; said insert
sheet being smaller in size than said outer base sheet and being
positioned on said outer base sheet so that said plurality of edge
portions of said outer base sheet extend beyond said edges of said
insert sheet wherein said insert sheet is not attached to said
outer base sheet along the plurality of edges.
10. The thermally insulated container of claim 9 wherein said
insert sheet is made of said insulating material.
11. The thermally insulated container of claim 10 wherein said
insulating material is selected from the class consisting of
corrugated material and foamed plastic.
12. The thermally insulated container of claim 9 wherein said base
sheet and said insert sheet are made of paper.
13. The thermally insulated container of claim 12, further
including a coating of reflective material on at least one side of
said insert sheet.
14. The thermally insulated container of claim 9 wherein said base
sheet and said insert sheet each have four bounding cut edges, two
of said edges being opposite side edges that are oriented at an
acute angle to each other, the other two of said edges being
opposite top and bottom edges that are curved and arc oriented
concentrically to each other.
15. The thermally insulated container of claim 9 wherein said
insert sheet is made of insulating material selected from the class
consisting of corrugated material and foamed plastic, said base
sheet and said insert sheet each having four bounding cut edges,
two of said edges being opposite side edges that are oriented at an
acute angle to each other, the other two of said edges being
opposite top and bottom edges that are curved and are oriented
concentrically to each other and said base sheet and said insert
sheet are made of paper.
16. The thermally insulated container of claim 9 wherein said outer
base sheet has a plurality of side edges that overlap and are
adhered together to form an overlapping edge area, said overlapping
edge area being adhered to said cup.
17. The thermally insulated container of claim 9 wherein said outer
base sheet has a plurality of side edges that overlap and are
adhered together to form an overlapping edge area, said insert
sheet being adhered to said cup.
18. The thermally insulated container of claim 14 wherein said cup
is made substantially from plastic material.
19. A container, comprising: a cup having a side wall and a bottom;
and an insulating wrapper wrapped around and adhesively attached to
the side wall of the cup, the insulating wrapper comprising: a base
sheet having a top edge, a bottom edge, and side edges; and an
insert sheet having a top edge, a bottom edge, and side edges
located between the cup and the base sheet such that the top edge
and bottom edge of the base sheet extend beyond the top edge and
bottom edge of the insert sheet wherein said insert sheet is not
attached to said base sheet along the top edge, the bottom edge and
the side edges of the insert sheet.
20. The container of claim 19, further comprising a generally
vertical strip of adhesive applied between the cup and the base
sheet for adhesively attaching the insulating wrapper to the
cup.
21. The container of claim 19, wherein the insert sheet is made of
a different material than either the base sheet or the cup.
22. The container of claim 19 wherein less than 20% of the area of
the insert sheet is adhesively attached to the base sheet.
23. The container of claim 19 wherein the side edges of the base
sheet are adhered to the cup such that the side edges are adjacent
to each other.
24. The container of claim 19 wherein the side edges of the base
sheet define a seam.
25. The container of claim 19 wherein the insert sheet is formed
from a foamed plastic.
Description
BACKGROUND
1. Field of Invention
This invention relates generally to insulating disposable cups and
containers, specifically to insulating wrappers, methods for
producing insulating wrappers, and methods for making insulated
containers with insulating wrappers.
2. Prior Art
Many types of cups and containers are available, each with a
specific set of characteristics relating to print quality,
rigidity, insulation, biodegradability, recyclability, clarity,
permeability, microwavability, and shelf life, among other
characteristics. Many types of cups have desirable features and
benefits in one or more areas, but undesirable features in other
areas.
E.g., cups made from expanded polystyrene (EPS), well known in the
art, are excellent thermal insulators and maintain the temperature
of a drink, whether hot or cold, for a long period of time. They
also provide a barrier between the hot or cold temperature of the
product and the user's hand. However EPS cups are generally
considered environmentally unfriendly because they are not
biodegradable. As a result, their use has been banned in some
municipalities. Also, in order to print EPS cups a slow and costly
off-line printing process must be used because the cups must be
printed after they have been formed, and their relatively rough
surface does not permit high-resolution printing.
Standard single-wall paper containers, also well known in the art,
are generally considered to be more environmentally friendly than
EPS cups, but they have poor insulating qualities. As such, many
coffee shops resort to double cupping, which is the practice of
serving a hot beverage in two stacked single-wall paper cups in
order to provide some level of insulation. This is a very expensive
and wasteful. Alternatively, designers have provided a number of
cup sleeves which are wrapped around a single wall paper cup to
provide insulation to keep drinks hot and hands comfortable; see,
e.g., U.S. Pat. No. 5,205,473 to Coffin (1993), U.S. Pat. No.
5,794,843 to Sanchez (1998), and U.S. Pat. No. 6,277,454 to Neale
et al (2001). One of the shortcomings of cup sleeves is that they
must be assembled and/or placed onto the cup when the beverage is
served. This requires extra labor and slows the speed of service.
Also the need for cups and sleeves require additional and
simultaneous purchasing, additional storage space, and additional
inventory management. Cup sleeves also have a tendency to fall off
of the cups, do not conveniently fit in all vehicle cup holders,
and cover the graphics printed on the cup.
Single-wall plastic cups made from materials such as polyethylene
terephthalate (PET), polystyrene (sometimes called PETE), (PS),
polypropylene (PP), and high density polyethylene (HDPE) are well
known in the art, and are formed through either thermoforming or
injection molding processes. Plastic cups are aesthetically
pleasing and can be made with high barrier properties to offer
longer shelf life to the products that they contain. A barrier
material called EVOH (Ethylene Vinyl Alcohol Polymer) can also be
added to provide a better oxygen barrier. A cup made from a thick
layer of HDPE will provide a significant moisture barrier. Plastic
cups made with both HDPE and EVOH are resistant to both moisture
and oxygen to provide extended shelf life to the products they
contain. Some types of plastic cups, such as those made from
polypropylene, are resistant to high levels of heat and as such are
microwavable. Also, plastic cups do not have a seam area, which
makes them relatively leak proof. However plastic cups must be
printed off-line after the cup is formed, which is an expensive
process and limits the graphic capabilities. Another problem is
that these cups are poor thermal insulators. They will loose their
heat or cool very quickly, and are uncomfortable to carry when
holding hot or cold contents. Another deficiency is that their
sidewall rigidity strength is poor.
Multi-layered paper cups have been designed to provide thermal
insulation and increased strength. U.S. Pat. No. 3,908,523 to
Shikaya (1975), U.S. Pat. No. 5,205,473 to Coffin (1993), U.S. Pat.
No. 5,547,124 to Mueller (1996), U.S. Pat. No. 5,685,480 Choi
(1997), U.S. Pat. No. 5,769,311 Morita et al. (1998), U.S. Pat. No.
5,775,577 Titus (1998), U.S. Pat. No. 6,039,682 Dees et al. (2000)
and U.S. Pat. No. 6,253,995 Blok et al. (2001) all show
multilayered cups with at least three layers, which include some
form of an inner cup made from paper and an outer cover or wrapper
to provide insulation. The wrapper comprises a multi-ply sheet
consisting of at least one base sheet, and at least one corrugated
or embossed sheet adhered to the base sheet. Although thermally
insulated and strong, these cups are expensive to manufacture
because the corrugated or embossed sheet must be adhered to cover
the entire surface of the base sheet through a lamination process.
This is a process whereby adhesive, such as hot melt or heated
polyethylene, or a paste adhesive such as a starch based cold glue,
is applied either to the surface of the embossed sheet and/or the
base sheet and the two sheets are pressed together forming a
multi-ply insulating sheet. The wrapper is then cut out (a process
called blanking) of this multi-ply sheet and wrapped around and
adhered to an inner cup. The process of laminating the sheets
together is expensive and wasteful. There is a significant amount
of value-added multi-ply sheet trim scrap which is wasted when
blanking the wrapper. There is also a significant amount of
adhesive used to secure the embossed sheet across the entire
surface of the base sheet, which is typically done along all of the
tips of the corrugations or embossments. The printing process is
expensive because either the base sheet must be printed prior to
laminating, which causes significant registration and distortion
issues after the sheets are laminated together, or the multi-ply
sheet is printed after the sheets are laminated, which is difficult
because of the thickness and stiffness of the multiply sheet and
the excess compressibility of the sheet. In any event, it is very
difficult to offer high quality printing at a cost effective price
on these types of insulated cups. Finally it is difficult to wrap
or bend the multi-ply laminated wrapper around an inner cup because
of the limited flexibility of thick laminated paperboard.
The insulated cups of U.S. Pat. No. 5,660,326 to Varano and Sadlier
(the present inventor) (1997), and U.S. Pat. No. 6,085,970 to
Sadlier (2000) have overcome these deficiencies. These cups have
gained widespread acceptance in the market and many millions have
been sold throughout the world. Although the cups of these two
patents are major improvements, I have discovered that both the
cups and their manufacturing processes can be improved even
further. Since the inner cup and the outer layer are made from a
continuous blank, these two parts are made from the same material.
This is disadvantageous since the inner layer must be made from
expensive polyethylene coated board for waterproofing and thus the
outer layer must also be made from this same expensive material.
Also, since the inner and outer layers are made from the same
blank, the entire blank, rather than just the outer portion of the
blank, must be passed through a printing press, which is a
relatively expensive processing operation. The sidewall blank must
also be folded in order to form the inner and outer layers of the
cup from the same elongated blank. The process of folding the blank
is an expensive additional step which requires precise
registration.
OBJECTS AND ADVANTAGES
Accordingly, several objects and advantages of the invention are to
provide an improved cup that has (a) improved thermal insulating
properties and rigidity. Also it can (b) be made of less costly
materials, (c) be made more leak resistant, (d) extend the shelf
life of the drink it contains, (e) be microwaved, (f) be made with
recycled materials, (g) be made from the most economical materials
for each part to save costs, (h) be printed more economically, (i)
be made without folding, and (j) be assembled at very rapid speed
with high-speed fabrication machinery. Further objects and
advantages will be apparent from a consideration of the ensuing
description and accompanying drawings.
SUMMARY
In accordance with one embodiment of the invention, a thermally
insulated container is formed from a single-walled paper or plastic
inner cup and an insulating outer wrapper. The insulating outer
wrapper comprises a paper base sheet or outer sidewall blank,
optionally printed on one side, and a corrugated paper insert. The
insert is similar in shape to the outer sidewall blank but its size
is smaller than that of the sidewall blank. The insert is glued in
a centered position of the non-printed side of the sidewall blank
to form a two-layered insulating wrapper. The two-layered wrapper
is then wrapped around a single walled inner cup, which is
positioned on a forming mandrel for support, with the insert to the
inside and the printed side of the blank to the outside. The side
edges of the wrapper overlap and are sealed together to form a side
seam. The insert or the side seam is itself adhesively secured to
the inner cup. The manufacturer can use other methods to adhere the
inner cup to the wrapper. E.g., they can use one or more beads of
cold glue (paste adhesive). Also they can pre-apply a thin layer of
polyethylene (or similar heat sealing material) to the inside cut
edges of the sidewall blank. This is then
heat-activated-immediately prior to wrapping the wrapper around the
inner cup, and pressing the overlapping side seam to the sidewall
of the inner cup to glue it in place.
DRAWINGS
Figures
FIG. 1 is a perspective view of a prior-art plain single-walled
paper or plastic cup.
FIG. 2 is a plan view of a flat paper base sheet used in an outer
wrapper according to the invention.
FIG. 3A is a plan view of a corrugated paper insert which is
attached to the base sheet.
FIG. 3B is an edge view of the corrugated paper insert of FIG.
3A.
FIG. 4A is a view of an outer wrapper consisting of an assembly of
the base sheet and corrugated insert.
FIG. 4B is an edge view of the outer wrapper.
FIG. 5 is a perspective view of the outer wrapper being wrapped
around a cup.
FIG. 6A is an elevational view of the wrapped cup and FIG. 6B is a
sectional view taken as indicated by lines 6B-6B in FIG. 6A.
FIG. 7 is a perspective view of the outer wrapper being wrapped
around a cup with a foamed plastic insert.
FIG. 8A is a view of an outer wrapper consisting of an assembly of
the base sheet and corrugated insert, with glue spots applied to
the insert for attaching the wrapper to the cup.
FIG. 8B is a cross-sectional view from above of the seam area of a
cup showing part of the wrapper of FIG. 8A attached to the cup.
DRAWINGS
Reference Numerals
TABLE-US-00001 10 side wall 10R upper rim 10B bottom 12 base sheet
12G glue spot 12SG seam glue 14 corrugated insert 14F foamed
plastic insert
DETAILED DESCRIPTION
FIG. 1--Prior-Art Cup
FIG. 1 shows a view from below of a prior-art paper or plastic cup.
The cup comprises a sidewall 10 an upper rim 10R, and a bottom 10B,
and is made of a single wall of plastic or plastic-coated paper. As
a result it has poor insulating qualities. Thus if it contains a
hot beverage (not shown) the heat will pass through the cup and
heat or burn the fingers of anyone who holds it. The cup could be
made of an insulating material, such expanded polystyrene (EPS), a
foamlike thick material, but EPS cups are generally considered
environmentally deleterious because they are not biodegradable and
thus their use has been banned in some areas. Also manufacturers
find it difficult to print trademarks and other messages on them.
The cup can be doubled, but this is an expensive and wasteful
practice. A cup sleeve can be slid over the cup, but this requires
additional labor, time, storage, and inventory management, and
sleeves have a tendency to fall off, do not conveniently fit in all
cup holders, and cover any graphics printed on the cup.
Multi-layered cups have been provided, but these have numerous
disadvantages, as noted above.
If made from paper, the cup is preferably made from solid bleach
sulfite (SBS) paperboard which is coated on at least one side with
polyethylene or any other suitable water proof material. The
process of making such a single-walled paper cup is well-known in
the art. It has a vertical side seam (not shown) that runs from the
bottom to the top of the cup. Different material combinations and
thicknesses can be used to achieve certain properties. For example,
if an insulated cup with a long shelf life is required, the paper
cup can be coated with a layer of foil on the inside. Foil provides
a great moisture and oxygen barrier to preserve the contents of the
liquid within. Alternatively, different thermoplastic barrier
materials can be coated onto the paper. E.g., HDPE and EVOH provide
moisture and oxygen barriers, respectively. If more sidewall
strength is required, the paper can be made thicker. If the
insulated cup is to be microwaved a waterproof material with a high
melting point, such as medium to high density polyethylene, can be
used.
If made from plastic, the cup may not have a side seam, and can be
formed from any of a number of materials, or combination of
materials, such as PET, PP, PS, and/or HDPE. The process of making
single-wall plastic cups from a thermoforming or injection molding
process is well known. Different material combinations and
thicknesses can be used to achieve certain properties. For example,
if an insulated cup with a long shelf life is required, the plastic
cup can be made from a combination of HDPE and EVOH. The HDPE
provides a moisture barrier which increases with the thickness of
the material, and the EVOH provides an oxygen barrier. If a
microwavable container is required, HDPE or PP can be used, both of
which are resistant to high levels of heat.
Insulating Outer Wrapper
FIGS. 2 to 4
In accordance with the invention, I provide an insulating outer
wrapper for use with the cup of FIG. 1. The wrapper comprises a
base sheet or layer 12 (FIG. 2) and an insert, sheet, or layer 14
(FIGS. 3A and 3B) which is attached to the base sheet. Both sheets
have the same shape, which is generally rectangular with four
bounding edges. Two of the edges are opposite side edges that are
oriented at an acute angle to each other, while the other two of
the edges are opposite top and bottom edges that are curved and are
oriented concentrically to each other. Layer 14 has corrugations or
other multiple distortions so as to cause it to be thicker than the
basic thickness of its material, thereby significantly increasing
its insulating properties and creating an insulating layer.
Presently for base sheet 12 I prefer to use Solid Bleach Sulfite
(SBS) paper, 0.20 mm to 0.50 mm thick. The base sheet is cut or
blanked from a larger starting sheet or roll (not shown) and has a
cut edge along the top and bottom arcs, and along each side. If the
finished cup is to bear a trademark and/or other printing, base
sheet 12 should be printed prior to being blanked from the larger
starting sheet or roll. The base sheet can be clay-coated in
well-known fashion on the print side to improve the smoothness and
brightness of the printing surface.
Corrugated insert 14 is formed by passing a flat sheet of paper
(preferably plate stock paperboard, cup stock, Kraft paper, or
linerboard which is 0.12 mm to 0.50 mm thick, and optionally coated
with a layer of reflective material such as metallized film or foil
as indicated) through an embossing or corrugating die (not shown),
and then cut to size in well-known fashion. Similar to the base
sheet, the corrugated insert has a cut edge along the top and
bottom arcs, and along each side. I prefer to form the corrugations
with a pitch (spacing between tops of adjacent ribs) of between 2.5
mm to 7.6 mm. The depths of the corrugations are 0.5 mm inch to
1.27 mm. Insert 14 is about 30% smaller in area than that of base
sheet 12. Due to the smaller size of the insert, if it is not
precisely centered on the base sheet as often happens with
high-speed assembling machinery, the insulating outer wrapper will
still be useable since the base sheet will still extend beyond the
edges of the insert.
Base sheet 12 and corrugated insert 14 are adhered together (FIGS.
4A and 4B) to form an insulating outer wrapper or assembly by
placing a small amount of glue 12G in a central area of, and
centered on, the base sheet, and attaching the insert. If the
insert material has a reflective coating on one side, the
reflective side would be positioned to face away from the base
sheet. Preferably less than 20% of the area of the insert is
adhesively attached to the base sheet. Note that since the insert
sheet is smaller than the base sheet, edge portions of the base
sheet extend beyond the edges of the insert. I presently prefer to
use hot melt adhesive because of its fast set time. Alternatively
the adhesive can be placed on the corrugated insert. As a further
alternative, several glue spots can be used in a central area of
the base sheet to provide more stability to the insert as it is
attached with high speed machinery. Unlike the prior art corrugated
cups, it is not necessary to use a large volume of glue to adhere
each of the tips of the corrugations to the base sheet as mentioned
above I prefer to glue less than 20% of the area of the corrugated
insert to the base sheet. In particular, no glue is applied to the
area adjacent to the cut side edges of the insert so that these
edges are free. The overall thickness of the finished insulating
outer wrapper, indicated in FIG. 4B, is between 1 mm to 2 mm
thick.
Container with Insulating Outer Wrapper
FIGS. 5 and 6
As shown in FIG. 5, the insulating outer wrapper or assembly of
base sheet 12 and corrugated insert 14 is assembled to the outside
of cup 10 of FIG. 1 by placing the cup on a mandrel (not shown) and
wrapping the insulating outer wrapper around the cup. This can be
done by well-known automated machinery. When the outer wrapper is
wrapped or curled in the manner shown in FIG. 5, the right and left
cut side ends of the inner or upper layer (insert 14) will tend to
migrate outwardly on the outer or lower layer (base sheet 12). If
the two layers were glued together over their entire areas, curling
or wrapping the assembly would tend to kink the insert, tear the
base layer, or pull the glued joint apart. Since insert 14 is not
attached to base sheet 12 along the side edges, the edges of the
insert can migrate freely and such undesirable results will not
occur.
When the insulating outer wrapper is fully wrapped around the cup
as shown in FIGS. 6A and 6B, the free cut edges of base layer 12
overlap and are glued together. This is done in any of a number of
ways. Preferably one or more beads of paste adhesive or hot melt
adhesive are applied to the overlapping edges of the base sheet and
then pressed together. Alternatively a layer of heat-activated
adhesive, such as polyethylene, can be pre-applied to the area
adjacent the cut edges of the base sheet and then heat activated to
seal the edges when they are overlapped and pressed together. The
insulating outer wrapper is itself adhered to the cup side wall
along the wrapper's vertical side seam area. This is done by
applying paste adhesive, hot melt adhesive, or a pre-applied
heat-activated polyethylene layer to the inside surface of the side
seam, which is then attached directly to the cup, or to a vertical
strip on the outside of the cup, to which the side seam is then
attached. The adhesive that attaches the side edges of the base
sheet together, and the adhesive that attaches the side edges of
the base sheet to the cup, are not shown in FIG. 6B.
In lieu of a thin layer of adhesive, a foaming adhesive can be used
to attach the overlapping edge areas of the base sheet to the cup.
One suitable foaming adhesive is sold under the trademark Airsperse
adhesive by H. B. Fuller Co., of St. Paul, Minn.; this glue
contains micro cells of air to provide a micro cell insulating
compound (not shown) that would space the overlapping side edges of
the base sheet from the cup and provide insulating properties.
The resultant insulated container of FIGS. 6A and 6B can contain a
hot beverage, yet can be held with one's bare hands. Very little
glue is needed since only a vertical strip of the wrapper (along
the side seam) and the cup are glued. Note that the overlapping
edges of base layer 12 are in contact with each other and with cup
10. The cut edges of corrugated insert 14 do not come between the
overlapping side seam of base sheet 12 and cup 10 since the
corrugated insert is shorter than base sheet 12. Thus it does not
interfere with the gluing of base sheet 12 to cup 10. Another
advantage of this is that it reduces the overall thickness of the
sidewall of finished insulated container. If standard corrugated
board were wrapped around a cup, there would be a double thickness
of the corrugated board at the overlapping side seam. This extra
thickness at the side seam would prevent the cups from nesting one
into one another. But by only having the base sheet overlap at the
side seam the overall thickness of the finished cup is not
increased. Additionally the manufacturer can glue the corrugated
insert, and thus the insulated wrapper, to cup 10 at one or more
circumferential locations around the cup for added stiffness and
strength.
I presently prefer to attach the insulating outer wrapper to cup 10
about 2.0 mm down from rim 10R so as to leave a an exposed area at
the top of the cup directly under the rim, but the wrapper can be
attached directly under the rim, or spaced farther down. I have
designed the dimensions of the insulated wrapper such that it does
not cover the entire vertical length of the cup. It is spaced up
from the bottom of the cup by approximately 1.6 cm to leave that
area of the cup's base exposed. Alternatively it can be sized to
cover the entire outside of cup 10, except for rim 10R. The wrapper
can also be sized to mimic the look of a cup sleeve wrapped around
a cup, whereby the cup side wall would be exposed above and below
the wrapper. The wrapper should just be large enough to cover and
thus insulate any area which will be held by the user.
The outside of the container can be printed more easily since only
base layer 12 need be passed though the printer. While cup 10
should be made of waterproof material (plastic or plastic-coated
paper), the outer insulating wrapper need not be made of this
expensive material since it does not contact the liquid and is not
part of cup 10.
Container with Foamed Plastic Insert
FIG. 7
In lieu of a corrugated paper insert 14 (FIGS. 3A to 5 and 6B), the
insert can be made of a layer of foamed plastic 14F, as shown in
FIG. 7. Layer 14F preferably is made of foamed PS, but also can be
made of foamed polyethylene, foamed PET, or any other closed or
open cell foamed plastic. A closed cell foam structure provides
better insulation than an open cell structure. Therefore I
presently prefer to use a closed cell foam material such as
extruded foam polystyrene. The blowing agent (gas) in the foam
(such as CO.sub.2 or butane) can also be varied to effect the
insulation. I prefer to use a blowing agent that provides superior
insulation. Layer 14F preferably is 0.5 mm to 1.5 mm thick. The
insulating qualities of layer 14F are comparable and even better in
some cases to those of corrugated layer 14, yet it can be adhered
to outer layer 12 and curled in the same manner as layer 14.
Gluing of Insert to Cup
FIGS. 8A and 8B
In lieu of gluing the edge area of the base sheet to the cup (FIGS.
6A and 6B), the insert sheet (corrugated or foam) can be glued to
the cup by applying several areas of glue 14G (FIG. 8A) to the
insert sheet or to the outside of the cup and then attaching the
wrapper (adhered insert and base sheet) to the cup. FIG. 8B shows
an enlarged sectional view from above of the seam area of cup 10
and the adjacent part of the wrapper. Specifically FIG. 8B shows
one spot of glue 14G attaching insert sheet 14 to cup 10 and seam
glue 12SG attaching the side edges of base sheet 12 together. Note
that the attached overlapping edge areas of the base sheet are
attached together, but are separated from the cup by air space,
which is insulating. In lieu of such air space, the foaming
Airsperse adhesive, supra, can be used to attach the overlapping
edge areas of the base sheet to the cup, in addition to attaching
the insert to the cup. Such adhesive (not shown) would fill the gap
between the overlapping side edges of the base sheet and the
cup.
CONCLUSION, RAMIFICATIONS, AND SCOPE
Accordingly the reader will see that, according to the invention, I
have provided a container with improved thermal insulating
properties and rigidity, and that also uses less costly materials,
is cheaper to make, is more leak resistant, extends the shelf life
of the liquid it holds, is microwavable, can be made from a higher
content of recycled content, can be made from the most economical
materials for each part to save costs, does not require folding,
and can be printed more economically. Wrapping the insulated
wrapper around a single wall plastic cup will provide an insulated
cup that, depending upon the plastic material of the inner cup, can
be leak proof, have extended shelf life, be microwavable, provide
rigidity to the plastic cup, provide better graphics to the plastic
cup, and will be potentially be less expensive than wrapping it
around a single wall paper cup (depending upon the type of plastic
material and thickness used). Due to the overlap of the base layer,
the insulating layer does not interfere with the gluing of the base
layer to itself or to the cup.
While the above description contains many specificities, these
should not be construed as limitations on the scope of the
invention, but as exemplifications of the presently preferred
embodiments thereof. Many other ramifications and variations are
possible within the teachings of the invention. For example,
although not necessary, the insulating insert, and thus the
insulated wrapper, can also be adhesively attached to the sidewall
of the inner cup in one or more locations, as this will provide
more rigidity to the finished cup. The insulating outer wrapper can
be wrapped into a cylinder and glued in this configuration,
whereafter the cup is then inserted into the wrapper. In lieu of
corrugations, the insert can be embossed with dimples, horizontal
corrugations, cruciform embosses, etc. As mentioned, the insert
sheet can be optionally coated with a reflective material, such as
foil or metallized film, which would be positioned to reflect
radiant heat back toward the inner cup. Also base sheet 12 (as well
as or in lieu of insert 14) can be embossed, corrugated, or made
from foamed plastic in order to provide the outside of the cup
wrapper with a textured look and feel and additional insulation
properties. The wrapper can also be adhered to the inner cup by one
or more beads of cold glue (paste adhesive) or a thin layer of
polyethylene (or similar heat sealing material) can be pre-applied
to the cut side edges of the base sheet. This is then
heat-activated immediately prior to wrapping the wrapper around the
inner cup, and pressing the overlapping side seam to the sidewall
of the inner cup to glue it in place. Since the inner cup and the
insulated wrapper can be made from different material, the base
sheet and/or corrugated insert can be made from recycled paper,
including clay-coated recycled paper for an improved printing
surface. The cup can be used to contain hot or cold solids as well
as liquids. The base sheet and the insulating insert can have
different shapes. E.g., if the cup is not tapered, the opposite
edges of the sheet and insert can be parallel.
Thus the scope of the invention should be determined by the
appended claims and their legal equivalents, and not by the
examples given.
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